f+s = 106
f+3 = 2(s-4)
now crank it out.
If the father's age in 3 years will be twice the son's age 4 years ago, and if the sum of their ages now is 106, how old is the father now?
5 answers
37
37
67
The correct answer is 67.
Here's how to solve it:
Let's use f for the father's age and s for the son's age.
From the first condition:
f + 3 = 2(s-4)
Simplifying this:
f + 3 = 2s - 8
f = 2s - 11
From the second condition:
f + s = 106
Substitute the first equation into the second:
(2s - 11) + s = 106
3s - 11 = 106
3s = 117
s = 39
Now we can use either of the two equations to find f:
f + 39 = 106
f = 67
So the father is currently 67 years old.
Here's how to solve it:
Let's use f for the father's age and s for the son's age.
From the first condition:
f + 3 = 2(s-4)
Simplifying this:
f + 3 = 2s - 8
f = 2s - 11
From the second condition:
f + s = 106
Substitute the first equation into the second:
(2s - 11) + s = 106
3s - 11 = 106
3s = 117
s = 39
Now we can use either of the two equations to find f:
f + 39 = 106
f = 67
So the father is currently 67 years old.